Cemu/src/Cafe/Filesystem/WUD/wud.cpp
2022-09-07 01:26:38 +02:00

128 lines
No EOL
3.8 KiB
C++

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "wud.h"
#include "Common/FileStream.h"
wud_t* wud_open(const fs::path& path)
{
FileStream* fs = FileStream::openFile2(path);
if( !fs )
return nullptr;
// allocate wud struct
wud_t* wud = (wud_t*)malloc(sizeof(wud_t));
memset(wud, 0x00, sizeof(wud_t));
wud->fs = fs;
// get size of file
long long inputFileSize = wud->fs->GetSize();
// determine whether the WUD is compressed or not
wuxHeader_t wuxHeader = {0};
if( wud->fs->readData(&wuxHeader, sizeof(wuxHeader_t)) != sizeof(wuxHeader_t))
{
// file is too short to be either
wud_close(wud);
return nullptr;
}
if( wuxHeader.magic0 == WUX_MAGIC_0 && wuxHeader.magic1 == WUX_MAGIC_1 )
{
// this is a WUX file
wud->isCompressed = true;
wud->sectorSize = wuxHeader.sectorSize;
wud->uncompressedSize = wuxHeader.uncompressedSize;
// validate header values
if( wud->sectorSize < 0x100 || wud->sectorSize >= 0x10000000 )
{
wud_close(wud);
return nullptr;
}
// calculate offsets and sizes
wud->indexTableEntryCount = (unsigned int)((wud->uncompressedSize+(long long)(wud->sectorSize-1)) / (long long)wud->sectorSize);
wud->offsetIndexTable = sizeof(wuxHeader_t);
wud->offsetSectorArray = (wud->offsetIndexTable + (long long)wud->indexTableEntryCount*sizeof(unsigned int));
// align to SECTOR_SIZE
wud->offsetSectorArray = (wud->offsetSectorArray + (long long)(wud->sectorSize-1));
wud->offsetSectorArray = wud->offsetSectorArray - (wud->offsetSectorArray%(long long)wud->sectorSize);
// read index table
unsigned int indexTableSize = sizeof(unsigned int) * wud->indexTableEntryCount;
wud->indexTable = (unsigned int*)malloc(indexTableSize);
wud->fs->SetPosition(wud->offsetIndexTable);
if( wud->fs->readData(wud->indexTable, indexTableSize) != indexTableSize )
{
// could not read index table
wud_close(wud);
return nullptr;
}
}
else
{
// uncompressed file
wud->uncompressedSize = inputFileSize;
}
return wud;
}
void wud_close(wud_t* wud)
{
delete wud->fs;
if( wud->indexTable )
free(wud->indexTable);
free(wud);
}
bool wud_isWUXCompressed(wud_t* wud)
{
return wud->isCompressed;
}
/*
* Read data from WUD file
* Can read up to 4GB at once
*/
unsigned int wud_readData(wud_t* wud, void* buffer, unsigned int length, long long offset)
{
// make sure there is no out-of-bounds read
long long fileBytesLeft = wud->uncompressedSize - offset;
if( fileBytesLeft <= 0 )
return 0;
if( fileBytesLeft < (long long)length )
length = (unsigned int)fileBytesLeft;
// read data
unsigned int readBytes = 0;
if( wud->isCompressed == false )
{
// uncompressed read is straight forward
wud->fs->SetPosition(offset);
readBytes = (unsigned int)wud->fs->readData(buffer, length);
}
else
{
// compressed read must be handled on a per-sector level
while( length > 0 )
{
unsigned int sectorOffset = (unsigned int)(offset % (long long)wud->sectorSize);
unsigned int remainingSectorBytes = wud->sectorSize - sectorOffset;
unsigned int sectorIndex = (unsigned int)(offset / (long long)wud->sectorSize);
unsigned int bytesToRead = (remainingSectorBytes<length)?remainingSectorBytes:length; // read only up to the end of the current sector
// look up real sector index
sectorIndex = wud->indexTable[sectorIndex];
wud->fs->SetPosition(wud->offsetSectorArray + (long long)sectorIndex * (long long)wud->sectorSize + (long long)sectorOffset);
readBytes += (unsigned int)wud->fs->readData(buffer, bytesToRead);
// progress read offset, write pointer and decrease length
buffer = (void*)((char*)buffer + bytesToRead);
length -= bytesToRead;
offset += bytesToRead;
}
}
return readBytes;
}
/*
* Returns the size of the data
* For .wud: Size of file
* For .wux: Size of uncompressed data
*/
long long wud_getWUDSize(wud_t* wud)
{
return wud->uncompressedSize;
}